GIÁ TRỊ SỬ DỤNG CỦA PHƯƠNG PHÁP RT-qPCR TIẾT KIỆM HÓA CHẤT CHẨN ĐOÁN SARS-COV-2 TỪ MẪU PHẾT TỴ HẦU

Abstract

Introduction: Key challenges for the effective Covid-19 pandemic control comprise financial burden and care capacity. The test detecting virus RNA in the nasopharyngeal swab by RT-qPCR is pivotal for the pandemic management in Vietnam. However, this technique possessed potential difficµLties, including slow turn-around time, high cost and the shortage of reagent supply. This study aims at SARS-CoV-2 testing procedure transformation to improve its effectiveness.  Materials and Method: Experimental study was carried out on the LightMix® Modular EAV RNA Extraction Control kit (Roche, Switzerland), TaqPath™ COVID‑19 CE‑IVD RT‑PCR kit (ThermoFisher, US) and RNA samples extracted from volunteer nasopharyngeal swab. Reaction conditions related to its volume & primer and probe concentration were examined at the level that is as low as 50% of the manufacturer recommendation. At each condition, PCR technical quality specifications, testing precision, sensitivity and specificity were validated. Results: The RT-qPCR reaction performed with 50% of primer and probe concentration, either at volume of 20 µL or 10 µL, met the technical quality specifications for a PCR assay. The assay showed a good CV (less than 11%) between runs within the day and along 3 days while its sensitivity and specificity are 100%. Conclusion: The RT-qPCR procedure diagnosing SARS-CoV-2 in nasopharyngeal swab, that is performed in a reagent-saving manner, fulfills assay validation criteria and is ready to transfer to medical units.